1、 What is static electricity
Static electricity is static charge. Any two objects of different materials will generate static electricity if they are separated after contact.
2 Electrostatic electricity is mainly generated through friction, contact, separation and induction.
3 In daily life, common and obvious static electricity includes: lightning; Electric shock when walking on the floor mat and touching the handle in winter; The crackle of clothing in winter. These have no impact on our human body, but they have a great impact on electronic components and electronic circuit boards.
2、 Electrostatic protection
(1) Hazards of static electricity:
1 Electrostatic adsorption (micro dust pollution): the electrostatic adsorption force is proportional to the electrostatic amount.
2 Electrostatic discharge (ESD): The current of electrostatic discharge is proportional to the amount of static electricity. The destructive energy caused by the current of electrostatic discharge may not only damage the product, but also cause RF interference and affect the production and operation of computer control programs.
3 Examples of electrostatic hazards in the electronic industry:
A Chip manufacturing:
----Electrostatic adsorption of fine dust particles, contaminating the chip
----RF generated by electrostatic discharge interferes with production and makes the machine stop without reason
B Integrated circuit:
----Electrostatic discharge breaks through the oxide layer, causing short circuit
----The discharge current of electrostatic discharge melts part of the circuit of the metal layer, causing an open circuit
----The high temperature generated by electrostatic discharge changes the properties of semiconductor and causes abnormal operation.
----Electrostatic discharge causes some micro damage. When the finished product is in normal operation, the micro damage will expand, causing the failure of the final product.
C Assembly of integrated circuit on circuit board:
Electrostatic discharge effect may occur during plug-in, welding or maintenance, which may damage the components on the board
D Manufacture of LCD:
----Electrostatic adsorption of fine dust on the glass, causing pollution
----Static electricity remains between two pieces of glass, which will affect the display of the LCD when discharging
In short, there are two main phenomena of electrostatic hazards:
1. Complete loss of function: the device cannot be operated, which accounts for 10% of the components damaged by static electricity
2 Intermittent loss of function: the device can be operated but its performance is unstable, which increases the number of repairs, accounting for 90% of the components damaged by static electricity
